Problem: If $2a + 4b + c = 4$ and $7x + y = -8$, what is $-12a - 24b - 6c + 70x + 10y$ ?
Solution: $= -12a - 24b - 6c + 70x + 10y$ $= (-6) \cdot (2a + 4b + c) + (10) \cdot (7x + y)$ $= (-6) \cdot (4) + (10) \cdot (-8)$ $= -24 - 80$ $= -104$